1. Field of the Invention
This invention relates to a latch device, and in particular to a sliding door latch.
While the device of the present invention was originally designed as a latch for a patio or other sliding door of the type including a fixed panel and a slidable panel, it will be appreciated that the device can also be used with other sliding doors and windows.
Often (for example during summer nights), it is desirable to leave a patio door partly open for ventilation purposes. However, even if an outer screen door is locked, such a practice can be quite dangerous.
2. Discussion of the Prior Art
Sliding door latches already exist. Examples of such devices are described in U.S. Pat. Nos. 3,471,189; issued to J. M. Ness on Oct. 7, 1969; 3,583,743, issued to S. Newell on Jun. 8, 1971; 3,630,560, issued to N. C. Atkins et al on Dec. 28, 1971; 4,295,676, issued to J. A. Smith on Oct. 20, 1981; 4,318,559, issued to C. Burton on Mar. 9, 1982; 4,438,640, issued to R. E. Willis on Mar. 27, 1984 and 4,826,225, issued to W. G. Styles on May 2, 1989.
In general, existing devices of the type described in the above listed patents are intended to permit either opening or locking of a door in the fully closed position. Alternatively, existing latches or locks are unduly complicated in terms of structure or operation. If production of a device is labour intensive or relies on complicated elements, the device becomes so expensive that it is never mass produced or does not gain public acceptance.
Accordingly, a need still exists for a device which can be used for latching a sliding door partly open or closed.